If I told you who made God you’d just say, “Who made the person that made God?” and “Who made the person that made the person that made God?” - the answer wouldn’t satisfy.
The Bible says that God is infinite: he has no beginning and no end. Our minds don’t get that. But they do get that they don’t get it!
It’s like this:
Imagine you’re in space and you travel to the end of the universe(s) until there’s no further that you can go. Well, if you’ve got as far as you can go I guess there must be nothing. What does it look like? An empty space, I suppose. But an empty space is not nothing. It takes up room. It has a colour. Probably black. If there’s an empty space you could enter it, pass through it. Where would it end?
So we understand that our minds don’t get it. We get it in theory but can’t get our heads around it in practice.
God is like that. No beginning and no end. God “who is and who was and who is to come” Revelation 1:4.